# -*- coding: utf-8 -*-
"""
Created on Tue Oct 24 19:05:00 2023

@author: 楠川之木
"""
import re

def replace_road(address):
    pattern = r'\bROAD\b'
    replacement = 'RD'
    result = re.sub(pattern, replacement, address, flags=re.IGNORECASE)
    return result

# 测试代码
address = "this is road ....,This is ROAD,This is Road"
result = replace_road(address)
print(result)  # this is RD ....,This is RD,This is RD